Localization of a T-Cell Epitope of Superantigen Toxic Shock Syndrome Toxin 1 to Residues 125 to 158

Toxic shock syndrome toxin 1 (TSST-1) is a member of the staphylococcal enterotoxin superantigen family. So far, little is known about T-cell epitopes on superantigens. In this study, we developed an improved method for localizing T-cell epitopes on superantigens that involved synthetic peptides plus costimulation by CD28 or phorbol myristate acetate. Using this method, we localized a T-cell epitope to a 34-residue region, TSST-1 (residues 125 to 158), which possessed only two of four TSST-1-targeted β-chain variable element (Vβ) specificities of T-cell receptors in humans and mice, human Vβ2 and murine Vβ15.